In a domestic environment, many times it is required to continuously monitor a particular event. For example, if the event is cooking something in the oven or stove, one needs to keep track of the time the food is being cooked and assess its readiness. It is difficult to leave the cooking task and do something else in fear of it getting burnt and it is extremely cumbersome to keep checking to see if the cooking is ready or not, while doing other activities. It is namely often desired to do multiple activities at the same time, like watching TV while cooking.
Furthermore, if adjustment is needed to the cooking progress (e.g. it needs to be cooked longer), people need to go to the source (e.g. the oven, microwave, stove) to continuously check for this and adjust accordingly, which limits the possibility of doing other activities while cooking.
Some of the existing household devices, e.g. microwave, toaster, ovens are equipped with a timer. In the more advanced devices, when the timer runs out the devices are automatically turned off and sometimes produce a beep sound to call the attention of the user. More-sophisticated ovens as an example are computer controlled, which allows a wide variety of operating modes and special features including the use of a temperature probe to automatically shut the oven off when the food is completely cooked to the desired degree.
The event can also be related to that one expects family or friends to come over (or reach a particular destination), where the hostess always wonders when they would reach the desired destination. Often, the host calls the expected visitor being expected asking them whether they are on the way, where they are, how much time they have left, etc. This leads to many phone calls and unwanted task disruptions. Thus, there is a need of reassurance and clear expectation.